Numerical printing device



Oct. 25, 1938.

w. G. BRILL,

NUMERICAL PRINTING DEVICE Filed Dec, 50, 1936 Patented Oct. 25, 1938 UNITED STATES PATENT OFFICE NUMERICAL PRINTING DEVICE Willem Gerhard Brill, Johannesburg, Transvaal, Union of South Africa 8 Claims.

This invention relates to numerical printing devices, of the kind having a series of rotatable numbering wheels, representing units, tens, hundreds and so on.

At present, in devices of this kind, the several numbering wheels are rotated with a step-by-step motion (in the necessary order, and at the proper relative speeds, for consecutive numbering) by individual pawls acting on ratchet teeth on the Wheels. The pawls are customarily mounted on a common carrier oscillated (in synchronism with the successive operations of printing) by a spring-plunger acted on by the platen or equivalent of the printing machine.

These known devices are open to a serious objection in that, at times, the pawls do not advance the numbering wheels the exact distance required. As a result, the numbers are printed incorrectly, and a whole sequence of printed sheets or the like may be spoiled.

The object of the present invention is to provide numerical printing devices which will be more reliable than heretofore, even at high printing speeds.

According to the invention, I provide numerical printing devices of the kind stated in which the step-by-step motion of the tens, hundreds, and other multiple-unit wheels is effected by inter-engageable teeth or other coupling elements thereon, and in which each said wheelthrough the said teeth or elements-is connectible, at, and for, such time as is necessary for its successive step-movements, to the lower multiple (or, in the case of the tens wheel. to the units) wheel adjacent, such units wheel being directly rotated-through pawl-and-ratchet means or otherwise-by, and in synchronism with, the platen or equivalent of the printing machine.

More specifically, the invention comprises numerical printing devices of the kind stated in which each numbering wheel has one of its numerals (9 for forward-numbering, and 0 for backward-numbering devices) formed or carried on a member which is slidable radially in the wheel and has a tooth projecting axially thereof, and in which the tens, hundreds, and other multiple unit wheels have each a series of fixed teeth projecting towards the radially slidable tooth adjacent, the units wheel being rotated step-by-step through means operated directly from the platen. or equivalent, and each radially-slidable member being moved so as to engage the tooth thereon with one of the fixed teeth adjacent, for the purpose of rotating the corresponding adjacent wheel through one stepmovement.

The radially-slidable member is movable preferably by cam means, which, as the numbering wheel concerned is rotated so as to bring the numeral 9 or 0 (whichever is borne by the said member) into printing position, causes the member to slide upwards to type level and the tooth thereon to abut against the uppermost of the fixed teeth adjacent, and which, as soon as the next step-movement of the said numbering wheel is completed, causes the member to be retracted, so as to disengage the said teeth, the corresponding adjacent numbering wheel, in the course of such movement, having been drawn round one step.

The invention, as applied to a numerical printing device of the backward-numbering type, will now be described by way of example, with reference to the annexed drawing, in which:

Fig. 1 is a View of the device in longitudinal section, its pawl mechanism being removed;

Fig. 2 is an end-sectional view taken on the line H-ll (Fig. 1) looking in the direction of the arrows;

Fig. 3 is a plan view of the device;

Fig. 4 is an end View of the pawl and ratchet mechanism (looking away from the plunger of the device) Fig. 5 is a view of the tens numbering wheel, 30 with its fixed teeth and a detent device;

Fig. 6 is a view of the units wheel, looking towards its radially-slidable member and cam;

Fig. 7 is a diagrammatic view of the fixed teeth of the tens numbering wheel and the path of the slidable tooth on the units wheel.

Referring to the drawing:-

The device has a frame I, in which a fixed hollow shaft 2 and a rotatable inner shaft 3 are mounted. At the left-hand end (Fig. 1) of the 40 shaft 3, a crank 4 is formed. With the ba1l-shaped end 5 of this crank, there engages a slotted dependent lug 6 on a plunger l. Guides 3 on the latter are slidable in vertical holes 9 in the frame, and a strong spring "I forces the plunger normally to its upper position, as illustrated. This spring is housed in a cup-shaped recess l l in the frame I and its upper end is centralized against he plunger by a ball-mounted spring-pressed cap I2. 50

The shaft 3, at its right-hand end (Fig. 1), is formed with a squared portion l3. On this, a carrier M- (Fig. 4) provided with spring-pressed pawls i5 is secured. These latter engage with a ratchet wheel l6, backward rotation of which is 55 prevented at all times by a spring-pressed catch II.

On the hollow shaft 2, the numbering wheels I8, I9, 20, 2| and 22 are rotatably mounted. These each carry type-numerals 0 to 9 arranged equidistantly round their circumferences (Fig. 3). The respective wheels mentioned denote units, tens, hundreds, thousands and tens of thousands. As will also be seen from Fig. 3, the top of the plunger I is formed with type-letters No.

Each numbering wheel I8 to 22 is provided with a cam disc 23 fixed on the hollow shaft 2. On the face of this disc, a cam slot 24 is formed. The type-numeral 0 of each numbering wheel is carried on a radially-slidable member 25, and a pin 25 thereon engages with the cam slot 24. On the side of the member 25, a tooth 21 is provided (see also Fig. 6); in the case of the numbering wheel 22, such tooth is omitted. A series of teeth 28 is fixed equiangularly round the face of each numbering wheel I9 to 22 directly opposite the respective tooth 21, the disposition of such teeth 28 corresponding to that of the typenumerals aforesaid.

Each numbering wheel l9 to 22 is formed with a decagonal rim 29. Against this, a detent-device 38 (Fig. 5) is pressed by a strong spring 3i. The strength of the spring is suiiicient to draw the angle of the wheel rim 29 into the V-shaped groove 32, should the wheel have over-reached or stopped short of its precise step-movement.

The modus operandi of the device is as follows:

The frame I is mounted in the usual manner on the type-bed (not shown). As a result, the plunger '1 is depressed at each printing operation by the platen or equivalent of the printing machine. By this means, the crank 4 is caused to rock the shaft.3, and the carrier I4 thereon draws back the pawls I5 over the ratchet wheel !6. The extent of backward movement is substantially equivalent to one ratchet tooth, there being ten such teeth in all. As will be apparent, the catch I7 keeps the wheel I6 stationary during this operation.

When the platen or equivalent recedes, and the plunger I rises under the action of spring ID, the crank 4 and carrier I4 cause the pawls [5 to force the ratchet wheel I 6 round the distance or" one tooth, i. e., f th of a revolution. In this position, the wheel I 6 is held by the catch I 7.

Since the ratchet wheel I6 is fixed to the units numbering wheel I8 (see key 33 in Fig. 1), the latter is also stepped forward 1 th of a revolution. This motion takes place each time the plunger 1 is depressed and released.

In practice, movement requires to be transmitted to the tens wheel I 9 only when the units wheel i 8 has printed in succession the type-numerals 9 to 0. Such transmission is effected as follows:

With the type-numeral l uppermost (Fig. 7), the tooth 2'! in wheel I8 will be at the po' sition 21 On the next step-movement of the units wheel l8, the tooth 21 (under the constraint exercised on the radially-slidable member 25 by the cam slot 24) is raised into abutment against the tooth 28 which is uppermost on the tens Wheel I9. In this position, the type-numeral 0 on the units wheel is uppermost, and after printing, it is moved th of a revolution to the left (Fig. 6). In the course of such movement, the tooth 2'Ithrough engagement with tooth 28 afcresaidcarries the tens Wheel I9 round Ihth of a revolution likewise. At the conclusion of this movement, the tooth 21 (under the constraint of the cam slot 24 on the member 25 of the units wheel) will be just free from the tooth 28 (see 21 Fig. '7). As a consequence, on the next stepmovement of the units wheel I8, the tens wheel I8 will be left undisturbed.

The same transmission action will take place between the units and tens wheels l8, l9 when the former has printed a further sequence of type numerals 9 to 0. Likewise, when the tens Wheel I9 has printed its full sequence of numerals, the type numeral 0 of such wheel (under the constraint of the corresponding cam slot 24) will have been raised, and the relative tooth 21 will be in engagement with the uppermost tooth 28 of the hundreds wheel 20 andat the next operation of the tens wheelswill carry such wheel 28 round one step. As will be appreciated, the transmission to the remaining wheels 2| and 22 is effected similarly.

Since, in many cases, it is not desired to print with all five numbering wheels I8 to 22 (e. g., when numbering only one thousand pages), it is customary in numerical printing devices to make the type numeral 0 of each wheel manually depressible below type level. In my invention, for this purpose, a notch 34 is provided in each cam slot 24, the pin 26 being depressible into this notch by simply moving the type-numeral 0" slightly beyond its uppermost position and thrusting the radially-slidable member 25 inwards. When the numbering wheels are in normal operation, there is no tendency, it is found, for the pin 28 to drop into the notch 34 accidentally, the tooth 21 on the member 25 being in frictional engagement at that point with the driven tooth 28.

It will be apparent that, since the plunger spring ID, in the case of four or five figure numbers, must supply the power to pull over from time to time a corresponding number of wheels, it should be made particularly strong, and that the strength of the detent springs 3| should be high likewise, though not, of course, so high as that of the spring I0.

Since only a single ratchet wheel I6 is necessary, duplicate pawls I5 can, as illustrated, be conveniently used, for reliability. Moreover, since the periodic coupling of the numbering wheels to one another depends solely on positively operated means, there is little or no danger of failure to rotate each wheel as and whenever required, even at high printing speeds.

I claim:

1. For a printing machine, a numerical printing device comprising a series of rotatable numbering wheels representing units, tens, hundreds and so on; a member radially slidable on each numbering wheel and having thereon one of the terminal numbers of the series on said Wheel; a tooth projecting from each member axially of said wheel; a series of fixed teeth projecting from each of said wheels and arranged for engagement by the tooth on the radially slidable member of an adjacent wheel; means for imparting step by step rotation to said units wheel; and means operative to actuate each slidable member radially of its wheel so that the tooth on such member is caused to engage one of the teeth on an adjacent wheel and rotate the latter.

2. For a printing machine, a numerical printing device comprising a series of rotatable numbering wheels representing unit, ten, hundreds and so on; a member radially slidable on each numbering wheel and having thereon one of the terminal numbers of the series on said wheel; a tooth projecting from each member axially of said wheel; a series of fixed teeth projecting from each of said wheels and arranged for engagement by the tooth on the radially slidable member of an adjacent wheel; means for imparting step by step rotation of said units wheel; and cam means operative to cause said slidable member to move radially to type level and engage its tooth with one of the fixed teeth on the adjacent numbering wheel as each numbering wheel is rotated to bring the terminal numeral of its series into printing position, said cam means being constructed and arranged so that when the succeeding one step movement of the numbering is completed the radially slidable member will be retracted and its tooth disengaged from the tooth on said adjacent numbering wheel which will have been rotated through a one step movement during such succeeding step movement of the numbering wheel carrying said member.

3. For a printing machine, a numerical printing device comprising a series of rotatable numbering wheels representing units, tens, hundreds and so on; a radially slidable member carried by said numbering wheels and having thereon one of the terminal numerals of the series of numerals on said wheel; a tooth projecting from each radially slidable member axially of its numbering wheel; a series of fixed teeth projecting'from each numbering wheel; means for imparting step by step rotation to the first numbering wheel of said series; and cam means operative to cause the slidable member carried by such wheels to move radially into type level position and engage its tooth with one of the teeth on the adjacent numbering wheel to rotate the latter as each numbering wheel is rotated to bring one of the terminal numerals of the series thereon into printing position, said cam means being constructed and arranged so that said radially slidable member is retracted below type level when slightly offset from printing position and rotation of the adjacent wheel limited to one step.

4. A numerical printing device as claimed in claim 1 comprising decagonal rims on the tens and other multiple unit wheels and spring detent devices having grooved members adapted to engage with the angles of said rims.

5. A numerical printing device as claimed in claim 3 wherein the cam means comprises notched means constructed and arranged so that the radially slidable member is depressible below type level when slightly offset from its printing position.

6. For a printing machine, a numerical printing device comprising a series of rotatable numbering wheels; a member radially slidable on each numbering wheel; a tooth projecting from each member axially of said wheel; a series of fixed teeth projecting from each of said wheels and arranged for engagement by the tooth on the radially slidable member of an adjacent wheel; means for imparting step by step rotation to one of said wheels; and means operative to actuate each slidable member radially of its wheel so that the tooth on such member is caused to engage one of the teeth on an adjacent wheel and rotate the latter.

7. For a printing machine, a numerical printing device comprising a series of rotatable num-- bering wheels; a member radially slidable on each numbering wheel; a tooth projecting from each member axially of said wheel; a series of fixed teeth projecting from each of said wheels and arranged for engagement by the tooth on the radially slidable member of an adjacent wheel; means for imparting step by step rotation to one of said wheels; and cam means operative to actuate each slidable member radially of its wheel so that the tooth on such member is caused to engage one of the teeth on an adjacent wheel and rotate the latter, said cam means being constructed and arranged so that when the succeeding one step movement of the numbering is completed the radially slidable member will be retracted and its tooth disengaged from the tooth on said adjacent numbering wheel which will have been rotated through a one step movement during such succeeding step movement of the numbering wheel carrying said member.

8. A numerical printing device as claimed in claim 6 wherein decagonal rims are provided on certain of said wheels together with spring detent devices having members adapted to engage with the angles of said rims.

WILLEM GERHARD BRILL. 

